Evaluation of Retinal Nerve Fiber Layer and Optic Nerve Head Measurements for Early Glaucoma Detection Using Optical Coherence Tomography

Abstract

Objective To evaluate the significance of the retinal nerve fiber layer (RNFL) thickness and optic nerve head parameters measured by optical coherent tomography (OCT) in the early diagnosis of glaucoma, combined with visual field change. Methods Thirty-six eyes of glaucoma patients, 34 eyes of suspected glaucoma and 10 healthy eyes were included in this study. All patients performed ONH and RNFL thickness examination with OCT during the same visit. Comparisons were made with regard to each quadrant and average RNFL thickness. Comparison of Cup/Disc horizontal and vertical ratio and area ratio were made between each group. Analyze the correlation between the average RNFL thickness and visual field. Results There was significant difference of RNFL thickness and optic disc parameters in various quadrants and means among the three groups (P< 0.05). Normal and SACG group: RNFL thickness in superior, inferior and the average was significant difference. Normal and CACG group: Every quadrant and average RNFL thickness was significant differences. CACG and SACG Group: the superior, inferior, nasal and the average of RNFL thickness was significant difference. The average RNFL thickness and visual field mean defect (MD) showed a strong and positive linear relationship. Conclusions OCT can early reflect the changes of glaucoma in RNFL thickness and optic disc parameters, also can find the RNFL thickness damage before the of visual field changes, and have a better correlation with the vision. It can serve as a method of early diagnosis of glaucoma. Key words: Optical coherence tomography; Retinal nerve fiber layer; Cup/Disc ratio; Glaucoma; Diagnosis